Outstanding chiroptical features in thin films of chiral π-conjugated oligomers: a from synthesis to applications

In the last years, chirality has gained an increasing interest in the fields of metamaterials and organic optoelectronics as an important parameter for controlling supramolecular arrangement of π- conjugated systems at different hierarchy levels, opening the way to highly innovative technological applications.[1] Most of these devices are based on the different interaction of the active layer with leftand right-handed circularly polarized light, therefore a current research goal is to obtain thin films of organic π-conjugated systems displaying significant chiroptical properties in absorption (i.e. electronic circular dichroism, ECD) or in emission (i.e. circularly polarized luminescence, CPL). In the present work we developed a family of novel chiral π-conjugated oligomers functionalized with inexpensive alkyl chiral groups from natural sources, studying their ECD and CPL features in thin films. Although in general we found a manifold of situations, revealing the central role of different local supramolecular structures (strictly related to chemical structure, deposition technique and postdeposition operations), in some cases we discovered outstanding chiroptical features.